1. Field of Invention
The present invention relates to an optical transceiver module, suitable for optical transmission through a small LAN.
2. Related Art
The application of optical fiber communication has been extended from long-distance telecommunication network and cable TV network to short-distance LAN and client loop. Optical communication devices and their production are crucial to optical fiber communication technology. In the future, it can be expected that optical fiber communication networks will be popularized to domestic appliances. At that time, active devices and module technology will play a preponderant role in such an advance.
An optical transceiver module is mounted in an electronic device for optical transmission via the optical fibers of an optical transceiver module. FIG. 1 is a perspective view of an optical transceiver module. The optical transceiver module includes a casing 11, a base 12, an optical receiver 13, an optical transmitter 14, a receiver circuit 15 and a transmitter circuit 16.
The base 12 carries the receiver circuit 15 and a transmitter circuit 16. The casing 11 covers the base 12 to protect the components therein. The receiver circuit 15 and the transmitter circuit 16 are respectively provided with a receiver chip and a transmitter chip respectively for optical signal processing and transmission driving. Optical transmission/reception of the electronic device is performed via pins 151, 161 respectively formed on the receiver circuit 15 and the transmission circuit 16 in the base 12.
However, since the optical receiver and the optical transmitter are integrated in a casing of the optical transceiver module, some problems may occur concerning heat dissipation, the arrangement of the optical fibers, and the alignment of the pins of the circuit board with through holes of substrates of other electronic devices, electromagnetic interference and electromagnetic radiation. These issues are discussed in detail as follows.
1. Heat dissipation:
The whole optical transceiver module includes a plurality of optical receivers and optical transmitters. Heat mainly comes from the receiver chip and the transmitter chip of the receiver and the transmitter. Heat only can be spread out through convection inside the closed space of the optical transceiver module. Therefore, heat dissipation efficiency is not satisfactory.
2. Arrangement of optical fibers:
Although a commercially available optical fiber connector can be adapted to connect the optical fiber, the optical receiver 13 and the optical transmitter 14, additional fitting still may be needed to match these elements with one another, which is inconvenient in use.
3. Alignment of the pins of the circuit board with through holes of substrates of other electronic devices:
The pins 151 of the receiver circuit 15 and the pins 161 of the transmitter circuit 16 connect to the substrate of the electronic device as interconnection. It is difficult to precisely insert so many pins in corresponding insertion holes of the substrate at one time, especially when one lead is bent or deformed.
4. Electromagnetic radiation and electromagnetic interference:
With the demand of smaller size and lightweight devices, a pitch between the receiver and the corresponding optical transmitter in the optical transceiver module has to be small. Electrical current of the optical transmitter generates electromagnetic radiation that jams the reception of high-frequency signal at the receiver. If the light intensity is small, the signal at the optical transmitter jams the signal at the receiver, which seriously affects the precision of signal reception.